We propose to continue our studies of the Zn 2 ion - catalyzed, poly(C)-directed polymerization of guanosine-5'-phosphorimidazolide (ImpG) and related compounds. Specifically, we propose to investigate: 1) the use of polypeptides as co-catalysts together with Zn 2 ion to increase the efficiency and the regiospecificity of the reaction; 2) the use of short templates such as CpCpC or GpGpG instead of polynucleotides such as poly C and poly G; 3) the template-directed reactions of activated dinucleotides such as ImpCpG.